Field of the Invention
Embodiments of the present invention relate to an organic light emitting display device and a method for manufacturing the same.
Discussion of the Related Art
According to a recent development of multimedia, there is an increasing demand for a flat panel display. In order to satisfy this increasing demand, various flat panel displays such as liquid crystal display device, plasma display panel, and organic light emitting display device are practically used. Among the various flat panel displays, the organic light emitting display device has been attracted great attentions owing to a rapid response speed. In addition, since internal elements included in the organic light emitting display device are formed of a solid material, the organic light emitting display device has good durability against external forces, and also enables a wide range of use temperature.
Especially, a manufacturing process of the organic light emitting display device is simplified so that it is possible to reduce a manufacturing cost in comparison to a related art liquid crystal display device.
FIG. 1 illustrates an organic light emitting display device of a bottom emission type according to the related art.
As shown in FIG. 1, the organic light emitting display device 10 include a first substrate 1, and a second substrate 2 confronting the first substrate 1, wherein the first substrate 1 and the second substrate 2 are provided with a predetermined interval in-between, and are encapsulated and bonded to each other by the use of sealing pattern 20 provided along the edges thereof.
In more detail, a driving thin film transistor (DTr) is formed in each of pixel regions (P) on the first substrate 1. Also, a first electrode 11, an organic light emitting layer 13, and a second electrode 15, which constitute a light emitting diode (E), are sequentially deposited on the first substrate 1. The first electrode 11 is electrically connected with the driving thin film transistor (DTr).
In this case, the first electrode 11 is formed of a transparent conductive material, and the second electrode 15 is formed of an opaque conductive material. Accordingly, light emitted from the organic light emitting layer is guided toward the first electrode 11.
Meanwhile, in order to prevent a lifespan of the organic light emitting display device 10 from being shortened by heat generated for a driving mode and degradation of the driving thin film transistor (DTr), as shown in FIG. 1, a heat insulating plate 30 is attached to an outer surface of the second substrate 2.
According as the organic light emitting display device of the related art is increased in size, an area of the second electrode 15 is increased so that a resistance value is increased, whereby a voltage drop (IR drop) might occur. Also, power consumption is increased by the increase of voltage drop according to the increase of resistance in the second electrode 15, and luminance of the organic light emitting display device is not uniform, whereby it is difficult to realize good reliability in the organic light emitting display device.
There has been proposed a method for increasing a thickness of the second electrode 15 so as to prevent the voltage drop caused by the increase of resistance in the second electrode 15. However, even though the voltage drop can be prevented owing to the increased thickness of the second electrode 15, a manufacturing cost of the organic light emitting display device is raised, and the organic light emitting display device is increased in its weight and thickness.
Especially, since the organic light emitting display device of the related art uses the carbon-based heat insulating plate, the organic light emitting display device of the related art is more increased in its weight and thickness.